H003: The pre-weaning maternal environment does not modulate the BP response to salt in the Sabra rat model of hypertension

• Published in: American journal of hypertension Vol. 13; no. S2; pp. 271A - 272A
• Main Authors: Yagil, Y., Yagil, C.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.04.2000
• Subjects: experimental models; foster mother; Sabra rats; salt-sensitivity
• ISSN: 0895-7061; 1879-1905; 1941-7225
• DOI: 10.1016/S0895-7061(00)01012-8

Background: Previous studies in SHR and Dahl rats have shown a significant impact of the maternal environment on the evolution of the BP phenotype. SHR raised by Wistar-Kyoto or Sprague-Dawley had attenuation of BP at 3 months. Similarly, Dahl S rats nurtured prior to weaning by Dahl R had a lower BP. In addition, in SHR and Dahl S, maternal environment has been demonstrated to have a significant impact on the BP response to salt. Objectives: To test the hypothesis that the maternal environment immediately after birth modulates the expression of the salt-susceptibility genes and affects the BP response to salt-loading (salt-sensitivity and salt-resistance) in the Sabra rat model of hypertension. Methods: The BP response to salt-loading was studied in SBH/y and SBN/y of both sexes in animals that had been nourished from immediately after birth and until weaning by a foster mother from the contrasting strain (reciprocal cross-fostering paradigm). Basal BP was measured shortly after weaning by the tail cuff method, animals were salt-loaded with DOCA-salt, and BP was measured again after 4 weeks. Results: Data are provided as mean±sem, n=9–16 in each experimental (Exp) group, F-female, M-male. The basal BP and the BP response to salt-loading in female and male SBH/y and SBN/y raised by foster mothers of the contrasting strains were not different from those observed in animals of the same strains that had been raised by their natural mothers. Conclusions: Expression of the salt-susceptibility genes is not affected by the maternal environment after birth in the Sabra model of salt-sensitive hypertension. The lack of such potentially confounding environmental modulator adds further strength to this model as highly suitable and focused for the search of the salt-susceptibility genes. (See Table) Foster SBH/y Foster SBN/y Natural mother SBH/y Exp – SBN/y Exp – SBH/y SBN/y SBH/y Sex F M F M F M F M Basal BP (mmHg) 121 ± 2 125 ± 2 138 ± 1 137 ± 1 126 ± 1 128 ± 1 139 ± 1 140 ± 1 BP after salt-loaded 126 ± 1 128 ± 1 196 ± 2 195 ± 3 132 ± 6 130 ± 1 195 ± 2 192 ± 3